I'm not sure what format MS Picture viewer opens, and I wouldn't really trust that program anyway for giving you the "true" size of the image. Assuming you're exporting a raster image file (jpg, png, bmp, tiff) from illustrator, the first thing I would do is make sure you're exporting it at an appropriate resolution. 300 ppi for print or 72 ppi for screen/web. If you're viewing a vector version in MS Picture viewer (pdf, ai, eps), then I would expect Picture Viewer is just scaling up the image to fit the screen without regard for the "actual" size. Actually, I'm fairly sure Picture Viewer is probably hard-coded to just make its display as big as possible for the window or screen, regardless of the image format.
Two quick comments on the map. I would probably include an exit number from the freeway and move the "X" from the middle of the street to the appropriate side for the address.
As an aside, I'd hate to have a business at the intersection of "West 500 South" and "South 500 West". What a mouthfull! Actually, the whole area seems like a Fire/EMS nightmare.
I think you are spot on that Picture viewer scales up the image. In that case, what would you recommend viewing the images/maps in outside of the graphics program?
Yes, moving the "x" to the correct roadside is a great idea, thanks.